1. Field of the Invention
The present invention relates to an apparatus for a camera that winds or rewinds a film by using a reversible motor.
2. Description of the Related Art
A film winding-rewinding apparatus for a camera that utilizes an endless belt (a timing belt) for a first driving step, is conventionally proposed for noise reduction. However, the oscillations induced in the driving mechanism are not sufficiently reduced by using an endless belt alone, therefore noise reduction with an endless belt alone is insufficient. Further, for guiding an endless belt, and for preventing dislocation of the endless belt from the pulleys, flanges are necessarily provided for each side of the pulleys, so that assembly of the driving mechanism is complex and cumbersome.
Therefore, an object of the present invention is to provide a film winding-rewinding apparatus that has advantages in noise reduction. Further, another object of the present invention is to provide a film winding-rewinding apparatus that prevents belt dislocation while improving assembly.
According to the present invention, a film winding-rewinding apparatus for a camera is provided that comprises a driving pulley, a driven pulley, an endless belt, a rewinding fork, a winding spool, a selective transmission mechanism, and an idler.
The driving pulley is attached to a shaft of a reversible motor and the endless belt is tensioned around the driving pulley and the driven pulley, so that the driving pulley drives the driven pulley. The rewinding fork engages with a spool of a film cartridge for rewinding the film, which is extended from the film cartridge, and a winding spool is provided for winding the film. The selective transmission mechanism alternatively transmits drive power from the driven pulley to the winding spool when the reversible motor is driven in a positive direction, and to the rewinding fork when the reversible motor is driven in a negative direction. The idler is disposed in the vicinity of the endless belt and engages with a side of the endless belt which is loosened when the reversible motor is driven in the negative direction, so that the idler gives tension to the endless belt.